So the whole purpose of 12. e4 is to open up the 3rd rank for the queen to attack the g file. Bishop on e7 was in a very good position and did not need to be moved. The best move would have been 12... Ng4 as it would have blocked the g file, making 12. e4 a bit of a mistake, and preparing for Nxf2 forking the rook and the queen. It would have put me on the defensive, but I was betting that you wouldn't see it.